valve stem holes

Dear Fellow Bicyclists, I've got wheels that originally had presta valve size holes, but were drilled out to accomodate shraeder. Can I install presta again despite the larger holes? Will it be a problem? Any help would be appreciated. Thanks, Jeremy

If the Son therefore shall make you free, ye shall be free indeed. John 8:36

At the very least, you will need to leave the 'dorknut' on the valve stem.
Did the person who drilled the thing know what he was doing? If it's on a skinny road rim, the rim is probably weakened and will likely fail catastrophically on you.

Ive used presta valves in wide drilled schreader holes for years without problems. Make sure the edges of the hole are smoothed with some emery cloth.
I do have problems with "aero-rim" long valved inners. They lack a thread for the dorknut, so dont seat well and move around when I try to pump it up..

I once put one of my Presta inner tubes on my son's Schrader-drilled mountain bike, and the tube started to bulge through the hole. Since then, I have had good luck using thin steel washers whose ID matches the OD of a Presta valve stem, and whose OD exeeds that of a Schrader. I put the washer against the rim, then apply my Velox tape over it.

Originally posted by chewa That's a good tip JohnE. I nearly bought some puncture sealant filled tubes for my last tour but was put off because they only came in schraeder. I wasn't keen on drilling my Wolber Champion rims.

might think again.

If you're looking at Slime tubes, they're now available in Presta.

Richard

Currently riding an MTB with a split personality - commuting, touring, riding for the sake of riding, on or off road :)

Thank you all for all your help with this little dilema. I don't know why anyone would drill out their rims either, but I could tell that it was a home-done job 'cause they were rough. In case you were wondering about what I did, here's the scoop.
I considered the washer idea since it's the simplest and cheapest, but found that paying for the sleeves would be better since the rims are curved on the inside, and they're double-wall ( I didn't want water and stuff gettin' in through the gap in the outer wall ).
So I bought my new, slime-filled presta tubes, and the sleeves. When I opened the box, I was dismayed to find that the tubes didn't have that "dork nut" or the threads for it. Furthermore, the sleeves wouldn't fit the stem past the half-way point as that was where the rubber started. What I ended up doing was drilling out the sleeves to 17 / 64 inches, then smoothing out the rough edges. It worked great!
Thanks again everyone; you guys are awesome!!!
Sincerely, Jeremy

If the Son therefore shall make you free, ye shall be free indeed. John 8:36